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- 1. Dab tsi yog MERN pawg? Koj puas tuaj yeem piav qhia txhua yam thiab nws lub luag haujlwm?
- 2. Cov pawg MERN piv rau lwm cov khoom siv thev naus laus zis zoo li MEAN lossis LAMP li cas?
- 3. Piav seb koj yuav tau txais daim ntawv thov MERN li cas?
- 4. Piav qhia lub luag haujlwm ntawm cov khoom nruab nrab hauv Express.js. Koj puas tuaj yeem muab piv txwv ntawm kev cai nruab nrab?
- 5. Dab tsi yog qhov txawv ntawm React Class Components thiab Functional?
- 6. Koj puas tuaj yeem piav qhia txog kev ua haujlwm li cas hauv daim ntawv thov MERN?
- 7. Cov Lus Cog Tseg yog dab tsi thiab lawv siv li cas hauv MERN daim ntawv thov?
- 8. Koj tswj hwm lub xeev li cas hauv daim ntawv thov React? Piav cov ntsiab lus xws li Redux thiab Context API.
- 9. Piav lub hom phiaj ntawm cov ntaub ntawv package.json hauv daim ntawv thov Node.js.
- 10. Lub hom phiaj ntawm Webpack yog dab tsi, thiab nws siv li cas hauv React project?
- 11. Koj tsim cov phiaj xwm hauv MongoDB li cas, thiab qee qhov kev xav tseem ceeb yog dab tsi?
- 12. Piav indexing hauv MongoDB thiab yuav siv nws li cas los txhim kho cov lus nug?
- 13. Koj ua li cas txog kev sib raug zoo hauv MongoDB, xws li ib-rau-ib thiab ntau-rau-ntau txoj kev sib raug zoo?
- 14. Dab tsi yog Aggregation Framework thiab MapReduce hauv MongoDB? Yuav ua li cas thiab thaum twg koj yuav siv lawv?
- 15. Koj li kev teeb tsa koj li Express.js txoj kev thiab cov tswj hwm li cas?
- 16. Koj puas tuaj yeem piav qhia txog kev ua yuam kev hauv Express.js?
- 17. Yuav ua li cas koj yuav siv authentication hauv daim ntawv thov Express.js?
- 18. CORS yog dab tsi thiab koj ua li cas hauv Express.js?
- 19. Piav txog React tivthaiv lub neej voj voog thiab cov txheej txheem cuam tshuam nrog cov txheej txheem kev ua neej sib txawv.
- 20. Koj ua li cas rau kev ua kom zoo ntawm daim ntawv thov React?
- 21. Piav qhia txog qhov sib txawv ntawm cov khoom tswj thiab tsis tswj xyuas hauv React.
- 22. Koj siv React Hooks li cas, thiab qee qhov kev siv feem ntau yog dab tsi?
- 23. Koj puas tuaj yeem sau ib qho yooj yim React tivthaiv uas nqa cov ntaub ntawv los ntawm API thiab qhia nws?
- 24. Piav lub virtual DOM hauv React thiab nws ua haujlwm li cas.
- 25. Koj tswj hwm kev vam meej hauv qhov project Node.js li cas?
- 26. Piav qhov Event Loop hauv Node.js. Nws ua haujlwm li cas asynchronous?
- 27. Cov kwj hauv Node.js yog dab tsi, thiab koj yuav siv lawv li cas?
- 28. Koj ua li cas rau pawg hauv Node.js siv tag nrho CPU cores?
- 29. Koj puas tuaj yeem sau cov haujlwm uas nyeem cov ntaub ntawv hauv Node.js siv ob qho kev hu rov qab thiab cov lus cog tseg?
- 30. Sau ib txoj haujlwm los txuas rau MongoDB thiab khaws tag nrho cov ntaub ntawv los ntawm ib qho kev sau tshwj xeeb.
- 31. Ua kom yooj yim CRUD API siv Express.js.
- 32. Tsim ib qho React tivthaiv uas siv lub xeev thiab cov khoom siv los ua cov ntaub ntawv.
- 33. Koj yuav ua li cas thiaj li daws tau cov ntaub ntawv uploads hauv Express.js?
- 34. Sau ib qho kev ua haujlwm nruab nrab hauv Express uas teev cov txheej txheem thov, URL, thiab teev sijhawm.
- 35. Ua raws li cov neeg siv kev lees paub siv JWT hauv daim ntawv thov MERN.
- 36. Koj yuav ua li cas thiaj kuaj tau cov khoom tiv thaiv React? Sau cov ntaub ntawv sim yooj yim.
- 37. Tsim React nuv los tswj daim ntawv nkag.
- 38. Ua yuam kev tuav rau ib txoj hauv kev hauv Express.js.
- 39. Koj yuav ua li cas thiaj lis cov ntaub ntawv hauv lub sijhawm tiag tiag hauv daim ntawv thov MERN? Piav thiab sau tus lej snippet siv Socket.IO lossis cov thev naus laus zis zoo sib xws.
- 40. Piav qhia thiab siv caching hauv MERN daim ntawv thov kom ua tau zoo.
- xaus
Kev txhim kho lub vev xaib niaj hnub no tau nce mus rau MERN Stack, muaj zog fusion ntawm plaub lub thev naus laus zis.
MERN Stack muab cov neeg tsim tawm nrog qhov kawg-rau-kawg daws teeb meem thiab suav nrog MongoDB, NoSQL database uas ua kom yooj yim thiab ua kom muaj zog, Express.js, lub vev xaib minimalist rau kev tsim cov khoom APIs, React, Facebook lub tsev qiv ntawv rau kev tsim cov neeg siv dynamic thiab sib tham sib. interfaces, thiab Node.js, JavaScript runtime uas ua rau server-sab sau ntawv.
Qhov kev thov rau MERN Stack nce ntxiv vim tias ntau lub tuam txhab ua haujlwm los muab cov kev paub zoo hauv online, ua kom nws txoj haujlwm nyob hauv kev ua lag luam.
Nws nkag siab tias yog vim li cas kev paub txog MERN thiaj li muaj nuj nqis nyob rau niaj hnub no qhov chaw ua haujlwm cutthroat. Koj tau tuaj rau qhov chaw zoo tshaj yog tias koj yog tus tsim tawm sim tsim koj tus kheej hauv kev hloov pauv sai sai no.
Qhov blog no sim muab koj cov ntaub ntawv tseem ceeb thiab kev nkag siab xav tau kom ua tiav hauv MERN Stack kev xam phaj.
Peb yuav qhia koj txog txhua theem ntawm cov txheej txheem los xyuas kom meej tias koj tau npaj los qhia koj cov kev txawj ntse, los ntawm kev nkag siab txog qhov tshwj xeeb ntawm txhua qhov kev ua haujlwm kom dhau los ua tus kws tshaj lij hauv kev sau cov lej zoo.
Txawm hais tias koj yog ib tug novice kawm txog MERN lossis ib tus kws paub txog kev nrhiav kev txhuam, qhov blog no muaj cov ntaub ntawv tseem ceeb rau koj.
1. Dab tsi yog MERN pawg? Koj puas tuaj yeem piav qhia txhua yam thiab nws lub luag haujlwm?
Tsim kom muaj peev xwm thiab muaj zog hauv online daim ntawv thov yog ua tau los ntawm MERN pawg, pob khoom siv tshuab zoo sib xws. Lo lus "MERN" yog tsim los ntawm cov ntawv uas txhua tus sawv cev rau qhov tseem ceeb:
- MongoDB: Raws li cov txheej txheem database, MongoDB muab schema-tsawg NoSQL system uas lav tau yooj yim hauv kev ua cov ntaub ntawv thiab ua rau nws haum rau cov ntawv thov xav tau nrawm dua.
- Express.js: Qhov no rov qab kawg daim ntawv thov web lub moj khaum, uas ua haujlwm zoo nrog Node.js, ua rau nws yooj yim los tsim APIs txhim khu kev qha thiab tswj kev ua haujlwm ntawm server-sab.
- React: React yog lub tsev qiv ntawv pem hauv ntej kawg nrog lub hom phiaj tseem ceeb ntawm tus neeg siv interface. Lub virtual DOM nws muab ua rau kev ua kom zoo dua qub, thiab nws ua kom muaj txoj hauv kev los npaj UI cov khoom, txhim kho ob qho tib si neeg siv thiab kev loj hlob.
- Node.js: Cov khoom kawg ntawm pawg yog Node.js, JavaScript runtime uas ua rau cov programmers khiav JavaScript code server-sab. Cov txheej txheem kev loj hlob yog streamlined los ntawm kev sib koom ua ke ntawm cov lus siv ntawm cov neeg siv khoom thiab cov neeg rau zaub mov.
2. Cov pawg MERN piv rau lwm cov khoom siv thev naus laus zis zoo li MEAN lossis LAMP li cas?
Muab piv rau MERN pawg rau lwm cov pawg paub zoo xws li MEAN lossis LAMP, nws sawv tawm vim nws cov cuab yeej txiav-ntug thiab dynamic technology.
Txawm hais tias qhov tseeb tias MEAN thiab MERN siv tib yam peb yam, MERN siv React tsis yog Angular, uas nquag rub cov neeg tsim khoom nrhiav kev yooj yim dua thaum tsim cov neeg siv khoom sib cuam tshuam.
LAMP, uas muaj Linux, Apache, MySQL, thiab PHP, ntawm qhov tod tes, yog ib qho kev siv ntau dua rau cov txheej txheem sab nraud. Txoj kev kawm nkhaus rau LAMP tej zaum yuav siab dua rau JavaScript-tsim MERN thiab MEAN pawg vim nws siv cov lus sib cais thiab thev naus laus zis rau cov neeg siv khoom- thiab kev txhim kho server-sab.
MERN tau qhuas rau nws txoj hauv kev txhua-JavaScript, uas txhawb nqa txoj kev txhim kho ntau dua thiab kev sib koom ua ke. Qhov kev txiav txim siab ntawm MERN, MEAN, thiab LAMP feem ntau nqis los rau qhov kev xav tau tshwj xeeb, pab pawg muaj peev xwm, thiab xav tau kev txhim kho.
3. Piav seb koj yuav tau txais daim ntawv thov MERN li cas?
Ib lub tswv yim nyuaj uas ua qhov tseem ceeb ntawm cov ntaub ntawv kev ncaj ncees thiab cov neeg siv kev ceev ntiag tug yuav tsum tau ua kom ruaj ntseg daim ntawv thov MERN. Kev xa tawm cov txheej txheem kev lees paub muaj zog thiab kev tso cai, nquag siv JWT (JSON Web Tokens) kom paub meej tias tus neeg siv txheeb xyuas, yog qhov tseem ceeb ntawm lub tswv yim no.
Tsis tas li ntawd, kev tiv thaiv zoo li kev nkag siab zoo thiab kev coj noj coj ua yog qhov tseem ceeb los txo qhov tsis zoo xws li SQL txhaj tshuaj thiab Hla-Site Scripting (XSS). Siv cov lus npaj hauv MongoDB pab tiv thaiv kev txhaj tshuaj tiv thaiv ntawm sab database.
Daim ntawv thov kev ruaj ntseg tiv thaiv kev tawm tsam yog ntxiv dag zog los ntawm kev siv HTTPS nrog cov ntawv pov thawj SSL / TLS uas tsim nyog, uas ua rau muaj kev sib txuas ntawm cov neeg siv khoom thiab cov neeg rau zaub mov.
Los ntawm suav nrog cov txheej txheem kev nyab xeeb no, daim ntawv thov MERN tuaj yeem ntxiv dag zog los tiv thaiv qhov tsis zoo thiab muab kev nyab xeeb rau cov neeg siv khoom.
4. Piav qhia lub luag haujlwm ntawm cov khoom nruab nrab hauv Express.js. Koj puas tuaj yeem muab piv txwv ntawm kev cai nruab nrab?
Express.js's middleware ua raws li cov channel rau kev ua haujlwm thiab txhim kho cov ntaub ntawv thaum nws txav mus los ntawm daim ntawv thov, tsim cov kev sib txuas tseem ceeb ntawm cov lus thov thiab cov khoom teb.
Cov haujlwm no muaj kev nkag mus rau cov khoom thov, cov khoom teb, thiab cov haujlwm nruab nrab tom qab hauv lub voj voog thov- teb ntawm daim ntawv thov.
Kev tuav haujlwm xws li kev txiav, kev txheeb xyuas, lossis kev txheeb xyuas cov ntaub ntawv yog ib qho kev siv rau nruab nrab. Piv txwv li, cov hauv qab no tuaj yeem siv los tsim cov kev cai txiav tawm nruab nrab:
Cov lej no yuav sau cov ntaub ntawv hais txog txhua qhov kev thov tuaj, muab kev nkag siab ntawm lub sijhawm rau cov neeg siv cuam tshuam nrog daim ntawv thov. Cov neeg tsim khoom tuaj yeem hloov kho lawv cov cai, ua kom rov siv tau dua, thiab tswj kom huv si thiab zoo codebase los ntawm kev siv cov khoom nruab nrab.
5. Dab tsi yog qhov txawv ntawm React Class Components thiab Functional?
Cov khoom siv hauv chav kawm thiab cov khoom siv ua haujlwm yog ob lub ntsiab lus tshwj xeeb uas tau tshwm sim hauv lub ntiaj teb dynamic ntawm React programming.
Cov Cheebtsam hauv chav kawm, qhia los ntawm cov lus tseem ceeb hauv chav kawm, yav dhau los yog tib txoj hauv kev siv lub neej ua haujlwm thiab ua kom lub xeev sab hauv hauv ib feem.
Txawm li cas los xij, nrog rau qhov sib ntxiv ntawm Hooks hauv React 16.8, Cov Khoom Siv Ua Haujlwm - cov haujlwm yooj yim - tam sim no tuaj yeem nkag mus rau lub xeev thiab lub neej kev ua haujlwm, feem ntau ua rau cov lej luv dua thiab nkag siab yooj yim dua.
Cov khoom siv ua haujlwm feem ntau nyiam rau lawv qhov yooj yim thiab yooj yim ntawm kev sim, tab sis Chav Cheeb Tsam muab kev sib koom ua ke ntau dua thiab cov khoom taw qhia.
Qhov kev txiav txim siab ntawm ob feem ntau yog los ntawm pab pawg lossis ib tus neeg nyiam, kev sib koom ua ke, thiab qhov project tag nrho cov hom phiaj ntawm kev tsim vaj tsev. Txawm li cas los xij, qhov kev xav tau mus rau qhov kev pom zoo ntawm cov khoom siv ua haujlwm vim tias lawv cov syntax yooj yim dua thiab hloov tau yooj yim dua.
6. Koj puas tuaj yeem piav qhia txog kev ua haujlwm li cas hauv daim ntawv thov MERN?
Hauv daim ntawv thov MERN, routing yog txoj kev npaj uas coj cov neeg siv mus rau ntau yam URLs hauv daim ntawv thov web. Express.js tswj routing ntawm lub backend los ntawm kev qhia txog ntau qhov kawg kom cuam tshuam nrog cov txheej txheem HTTP tshwj xeeb thiab URLs, yog li tswj xyuas seb lub server cuam tshuam li cas rau cov neeg thov kev thov.
React Router thiab lwm yam thev naus laus zis hauv pem hauv ntej yog siv los tsim cov ntawv thov ib nplooj ntawv nrog rau txoj hauv kev navigation uas ua raws li cov lus pom ntau ntau nplooj ntawv.
Ua ke, cov txheej txheem routing no muab cov kev paub zoo rau cov neeg siv uas ua rau nws muaj peev xwm taug qab tau zoo yam tsis muaj nplooj ntawv tshiab.
MERN cov ntawv thov tuaj yeem muab cov kev ua haujlwm zoo, teb, thiab nkag siab zoo txog kev qhia txog kev ua haujlwm uas ua tau raws li cov qauv kev txhim kho hauv lub vev xaib thiab cov neeg siv kev cia siab los ntawm kev siv cov neeg siv khoom-sab thiab server-sab kev sib raug zoo.
7. Cov Lus Cog Tseg yog dab tsi thiab lawv siv li cas hauv MERN daim ntawv thov?
Ib qho zoo nkauj dua thiab tswj tau lwm txoj hauv kev hu rov qab yog muab los ntawm JavaScript cov lus cog tseg abstraction, uas yog qhov kev xav tsis zoo rau kev ua haujlwm asynchronous.
Cov lus cog tseg tau siv dav hauv cov ntsiab lus ntawm daim ntawv thov MERN los daws cov haujlwm uas tsis daws tam sim ntawd, xws li kev tshawb nrhiav database nrog MongoDB lossis HTTP thov nrog Express.js. Kev cog lus yog ib qho piv txwv ntawm tus nqi uas tej zaum yuav tsis muaj nyob tam sim no tab sis qhov ntawd yuav ua tiav lossis tsis lees paub yav tom ntej.
Cov neeg tsim tawm tuaj yeem qhia meej tias daim ntawv thov yuav tsum ua li cas tom qab Kev Cog Lus tau ua tiav lossis muaj qhov yuam kev tshwm sim los ntawm chaining the.then() and.catch() method.
Kev siv ntau zaus ntawm cov lus cog tseg hauv MERN daim ntawv thov ua rau cov lej meej dua thiab yooj yim dua rau kev tswj hwm, tso cai rau cov neeg tsim qauv tsim asynchronous code uas nkag siab ntau dua thiab yooj yim dua rau kev debug, txhim kho cov txheej txheem 'tag nrho cov txiaj ntsig thiab kev ua haujlwm zoo.
8. Koj tswj hwm lub xeev li cas hauv daim ntawv thov React? Piav cov ntsiab lus xws li Redux thiab Context API.
Hauv daim ntawv thov React, kev tswj hwm lub xeev tuaj yeem ua haujlwm tseem ceeb thiab nyuaj, tshwj xeeb tshaj yog tias daim ntawv thov nthuav dav hauv qhov loj thiab qhov nyuaj. Cov neeg tsim khoom nquag siv cov cuab yeej tswj hwm lub xeev xws li Redux thiab Context API los daws qhov teeb meem no.
Redux muaj ib qho chaw cia rau lub xeev ntawm tag nrho daim ntawv thov, tso cai rau kev txhim kho cov ntaub ntawv nkag mus thiab hloov kho thoob plaws ntau yam.
Redux cov kev ua thiab kev txo qis ua rau nws yooj yim dua los kwv yees thaum lub xeev yuav hloov pauv, uas txhawb kom muaj kev sib luag thiab kev tswj xyuas.
Ntawm qhov tod tes, cov neeg tsim khoom tuaj yeem tsim cov ntsiab lus uas tuaj yeem hloov pauv lub xeev thiab ua haujlwm nrog cov khoom siv zes siv React's built-in Context API yam tsis tas yuav muaj kev khawb av.
Cov ntsiab lus API muab cov kev daws teeb meem yooj yim dua thiab hnyav dua rau cov xwm txheej thaum lub ntiaj teb kev tswj hwm lub xeev xav tau yam tsis muaj qhov nyuaj ntawm cov tsev qiv ntawv ntxiv, tab sis Redux muab cov kev daws teeb meem ntau dua thiab muaj peev xwm, tshwj xeeb tshaj yog rau cov ntawv thov loj.
Ob txoj hauv kev muaj lawv qhov zoo, thiab kev xaiv feem ntau cuam tshuam los ntawm cov kev xav tau tshwj xeeb thiab daim ntawv thov architecture.
9. Piav lub hom phiaj ntawm cov ntaub ntawv package.json hauv daim ntawv thov Node.js.
Cov ntaub ntawv package.json yog ib qho tseem ceeb ntawm Node.js ecosystem vim nws ua hauj lwm hauv qhov tob rau txhua daim ntawv thov cov yam ntxwv.
Nws yooj yim rau kev teeb tsa cov txheej txheem rau lwm cov neeg tsim khoom lossis cov tshuab los ntawm kev qhia txog kev txhim kho tshwj xeeb cov kev xav tau ntxiv rau cov kev vam meej uas tsim nyog rau qhov project.
Cov ntaub ntawv tseem ceeb no tseem muaj cov ntaub ntawv tseem ceeb, xws li lub npe ntawm qhov project, cov lus piav qhia, thiab cov qauv tam sim no, ua kom yooj yim rau kev faib thiab cov ntaub ntawv. Tshaj li cov yam ntxwv tseem ceeb no, cov ntaub ntawv package.json muab cov neeg tsim khoom muaj peev xwm los tsim cov ntawv cim tshwj xeeb, ua cov haujlwm xws li pib lub server thiab ua cov kev xeem tseem ceeb yooj yim dua.
Thaum kawg, cov ntaub ntawv tseem ceeb no ua raws li cov Node.js daim ntawv thov architectural blueprint, ceev txoj kev loj hlob, txhawb kev koom tes, thiab guaranteeing txhim khu kev qha kev ua tau zoo nyob rau hauv ntau yam kev teeb tsa.
10. Lub hom phiaj ntawm Webpack yog dab tsi, thiab nws siv li cas hauv React project?
Tshwj xeeb, Webpack ua haujlwm raws li tus qauv bundler hauv React daim ntawv thov, ua rau nws yog ib qho tseem ceeb rau kev txhim kho lub vev xaib tam sim no.
Nws txoj hauj lwm tseem ceeb yog sau ntau cov ntaub ntawv thiab kev vam khom, xws li JavaScript, CSS, duab, thiab fonts, mus rau hauv ib pab pawg me me uas muaj peev xwm muab tau sai sai rau qhov browser.
Los ntawm kev ua qhov no, Webpack txhim kho kev nrawm vim tias muaj kev thov tsawg dua thiab cov lej tau muab rau hauv txoj hauv kev uas tsim nyog rau cov neeg siv kawg cov ntsiab lus.
Cov neeg tsim khoom tuaj yeem ua qhov kev hloov pauv, tso cai rau kev faib cov lej, thiab teeb tsa qhov hloov pauv kub siv Webpack, uas dhau mus dhau qhov yooj yim bundling thiab muab kev nplua nuj ecosystem ntawm plugins thiab ntau hom kev xaiv rau kev txhim kho ntau dua.
Ib txoj kev txhim kho yooj yim dua thiab tswj tau yooj yim uas ua rau ob qho tib si kev txhim kho yooj yim thiab kev tsim kho kom zoo yog txhawb nqa los ntawm kev sib koom ua ke Webpack rau hauv React project. Nws txoj haujlwm hauv React project qhia txog qhov kev txav mus los ntawm kev hloov pauv thiab kev ua tau zoo-kev paub txog lub vev xaib txhim kho.
11. Koj tsim cov phiaj xwm hauv MongoDB li cas, thiab qee qhov kev xav tseem ceeb yog dab tsi?
MongoDB schema tsim xav tau kev xav zoo nrog rau kev paub txog cov cai tshwj xeeb ntawm daim ntawv thov.
MongoDB's versatility raws li NoSQL database enables programmers los tsim schemas uas yooj yim adaptable rau ntau yam ntaub ntawv qauv.
Nws yog ib qho tseem ceeb uas yuav tsum tau coj mus rau hauv tus account qhov kev sib txuas ntawm ntau lub koom haum thaum tsim ib lub tswv yim, txiav txim siab seb puas yuav siv cov ntaub ntawv kos lossis cov ntaub ntawv raws li cov qauv nug thiab cov kev xav tau ua haujlwm.
Hom ntaub ntawv thiab kev nyeem ntawv thiab sau ntawv ua haujlwm li cas tshwm sim tuaj yeem cuam tshuam rau kev txheeb xyuas thiab kev xaiv ua kom zoo.
Cov ntsiab lus tseem ceeb hauv cov txheej txheem tsim qauv kuj suav nrog kev saib xyuas cov ntaub ntawv siv tau, cov kev xav tau sib xws, thiab yav tom ntej scalability.
Cov neeg tsim khoom tuaj yeem tsim kom muaj txiaj ntsig zoo thiab hloov kho cov qauv database uas txhawb nqa qhov kev vam meej mus ntev ntawm qhov project los ntawm kev sib piv cov qauv tsim nrog cov kev xav tau tshwj xeeb thiab cov yam ntxwv ntawm daim ntawv thov.
12. Piav indexing hauv MongoDB thiab yuav siv nws li cas los txhim kho cov lus nug?
Hauv MongoDB, indexing yog cov txheej txheem muaj zog rau kev txhim kho kev ua tau zoo thiab ceev ntawm cov lus nug. Lub database Performance index, zoo ib yam li qhov Performance index nyob rau hauv ib phau ntawv, enables MongoDB kom sai sai nrhiav cov ntaub ntawv tshwj xeeb yam tsis tau luam theej duab tag nrho cov sau, txhim kho cov lus nug.
Lub sijhawm nws yuav siv tau kom tau txais cov ntaub ntawv tuaj yeem txo qis los ntawm cov neeg tsim khoom los ntawm kev tsim cov indexes ntawm cov teb uas feem ntau tshawb nrhiav.
Tab sis nws yog ib qho tseem ceeb kom ua tiav qhov sib npaug vim tias kev ntsuas ntau dhau tuaj yeem ncua sijhawm sau cov haujlwm thiab siv cov khoom khaws cia ntxiv.
Thaum tsim cov indexes, nws yog ib qho tseem ceeb uas yuav tsum tau ua tib zoo xav txog cov qauv lus nug thiab muaj kev nkag siab zoo ntawm kev lag luam tawm ntawm kev nyeem ntawv thiab sau ntawv.
Nyob rau hauv qhov tseem ceeb indexing hauv MongoDB, thaum siv kom zoo nws tuaj yeem ua rau cov lus nug muaj txiaj ntsig zoo, pab txhawb kev teb thiab txhim khu kev qha.
13. Koj ua li cas txog kev sib raug zoo hauv MongoDB, xws li ib-rau-ib thiab ntau-rau-ntau txoj kev sib raug zoo?
Txawm hais tias kev sib raug zoo yog ib-rau-ib lossis ntau-rau-ntau, MongoDB tswj nws cov tswv yim raws li qhov xav tau thiab cov qauv nug ntawm daim ntawv thov.
If kev sib raug zoo yog ib-rau-ib, koj tuaj yeem txiav txim siab los sib txuas cov ntsiab lus txuas mus rau hauv cov ntaub ntawv tseem ceeb, uas yuav yooj yim rau cov txheej txheem nug.
Cov ntaub ntawv tuaj yeem siv los txuas cov ntaub ntawv hauv ntau-rau-ntau txoj kev sib raug zoo, uas tuaj yeem tsim nyog dua yog tias kev sib raug zoo yog qhov nyuaj lossis cov ntaub ntawv loj.
Cov ntaub ntawv redundancy, hloov tshiab zaus, thiab qhov tsim nyog rau schema saj zawg zog yuav tsum tau coj mus rau hauv tus account thaum xaiv ntawm embedding thiab referencing.
Kev tswj hwm kev sib raug zoo hauv MongoDB tuaj yeem ua rau muaj cov txheej txheem database ruaj khov uas ua tau raws li qhov xav tau ntawm daim ntawv thov nrog kev npaj ua tib zoo thiab kev paub txog kev lag luam tawm hauv lub hauv paus. Raws li kev xav tau tshwj xeeb thiab qhov muaj zog ntawm cov ntaub ntawv siv, kev xaiv ntawm embedding thiab referencing yog qhov tseem ceeb.
14. Dab tsi yog Aggregation Framework thiab MapReduce hauv MongoDB? Yuav ua li cas thiab thaum twg koj yuav siv lawv?
Rau kev ua thiab tshuaj xyuas cov ntaub ntawv hauv MongoDB, Aggregation Framework thiab MapReduce sawv ua cov cuab yeej muaj zog. Zoo ib yam li cov ntaub ntawv ua cov raj xa dej, Aggregation Framework muaj cov haujlwm zoo li kev lim, pab pawg, thiab txheeb xyuas thiab ua rau cov neeg tsim khoom sib sau thiab hloov cov ntaub ntawv hauv ntau theem.
Txhawm rau ua cov ntaub ntawv loj heev thoob plaws cov pawg sib cais, MapReduce muab txoj hauv kev hloov tau yooj yim dua los ntawm kev siv ob-theem ua haujlwm - Daim Ntawv Qhia thiab Txo.
Qhov nyuaj thiab qhov loj ntawm txoj haujlwm yuav tsum raug coj mus rau hauv tus account thaum xaiv seb yuav siv li cas: Aggregation Framework feem ntau siv rau kev ua haujlwm tsis tu ncua thiab cov txheej txheem me me, thaum MapReduce ci ntsa iab hauv cov ntaub ntawv nyuaj, cov ntaub ntawv loj.
Txhawm rau ua kom zoo dua cov ntaub ntawv ua haujlwm thiab xyuas kom MongoDB ua tau raws li daim ntawv thov kev tshuaj ntsuam xav tau, nws yog ib qho tseem ceeb kom nkag siab txog qhov zoo thiab qhov tsis zoo ntawm txhua lub cuab yeej.
15. Koj li kev teeb tsa koj li Express.js txoj kev thiab cov tswj hwm li cas?
Express.js txoj kev thiab cov tswj hwm yuav tsum tau teeb tsa hauv qhov kev xav tau thiab zoo ib yam uas ua kom tiav daim ntawv thov kev tsim tag nrho.
Routes thiab controllers feem ntau yuav tsum tau muab faib ua cov ntaub ntawv sib txawv thiab cov ntawv qhia kom khaws tau cov modularity thiab txhim kho kev ruaj ntseg.
Hauv txoj kev, tsim cov ntsiab lus sib txawv thiab txuas lawv mus rau qee yam HTTP txoj kev ua kom muaj kev nkag siab thiab tsim qauv tsim qauv. Cov kev ua haujlwm cuam tshuam nrog cov ntsiab lus kawg no yog tswj hwm los ntawm cov tswj hwm, thiab los ntawm kev ua kom lawv cais tawm ntawm txoj kev, cov codebase yooj yim rau kev sim thiab ntsuas.
Cov cai huv huv, muaj txiaj ntsig zoo ntxiv yog pab ntxiv los ntawm kev siv cov lus piav qhia npe, kev ua haujlwm nruab nrab, thiab kev ua haujlwm zoo.
Zuag qhia tag nrho, Express.js txoj hauv kev thiab cov tswj hwm uas tau xav txog tsim cov ntawv thov uas muaj zog thiab hloov tau txaus kom tau raws li qhov xav tau tam sim no thiab muaj peev xwm nthuav dav yav tom ntej.
16. Koj puas tuaj yeem piav qhia txog kev ua yuam kev hauv Express.js?
Express.js qhov kev ua yuam kev yog qhov tseem ceeb rau kev tsim cov apps uas muaj zog thiab siv tau zoo hauv online. Kev siv cov khoom siv nruab nrab tsim tshwj xeeb los ntes thiab ua cov txheej txheem yuam kev yog lub hauv paus ntawm txoj hauv kev no.
Cov neeg tsim khoom tuaj yeem tsim cov ntsiab lus tshwj xeeb los daws ntau yam kev ua yuam kev thiab muab cov lus teb muaj txiaj ntsig rau tus neeg siv khoom los ntawm kev txheeb xyuas qhov yuam kev-khiav nruab nrab nrog plaub qhov kev sib cav (err, req, res, thiab tom ntej).
Txhawm rau lav tias lawv ntes cov kev ua tsis tiav uas ua npuas los ntawm cov khoom nruab nrab thiab cov kev ua ntej, cov txheej txheem nruab nrab yuav tsum zoo dua muab tso rau hauv qab ntawm cov khoom nruab nrab.
Los ntawm maj mam hais daws cov teeb meem uas tsis tau xav txog, kev ua yuam kev kom raug tsis yog ua rau daim ntawv thov muaj zog dua, tab sis kuj txhim kho cov neeg siv kev paub los ntawm kev xa cov lus qhia yuam kev thiab cov lus qhia.
Kev ua yuam kev ntawm Express.js tuaj yeem hloov cov teeb meem nyuaj rau hauv txoj hauv kev kom pom tseeb thiab muaj peev xwm nyob hauv koj daim ntawv thov los ntawm kev ua tib zoo siv.
17. Yuav ua li cas koj yuav siv authentication hauv daim ntawv thov Express.js?
Kev ua raws li kev lees paub hauv daim ntawv thov Express.js yog txheej txheem nyuaj uas yog qhov tseem ceeb rau kev tswj xyuas kev nkag mus thiab tiv thaiv cov neeg siv cov ntaub ntawv.
Siv cov pob khoom xws li Passport.js, uas ua rau muaj ntau yam kev lees paub tus neeg siv, suav nrog kev lees paub hauv zos thiab OAuth nrog kev nkag mus hauv social network, yog ib lub tswv yim nquag. Tom qab tus neeg siv tau lees paub lawm, tus neeg siv lub xeev tuaj yeem tswj hwm ntawm kev thov siv ntu lossis JSON Web Tokens (JWT).
Los ntawm kev lees paub tias tsuas yog cov neeg siv kev lees paub tuaj yeem siv cov peev txheej tau hais tseg, cov haujlwm nruab nrab feem ntau ua si qhov tseem ceeb hauv kev tiv thaiv qee txoj hauv kev.
Cov txheej txheem nkag mus tau yooj yim dua rau cov neeg siv los ntawm kev ua yuam kev thiab cov lus teb meej.
Thaum kawg, nco ntsoov cov kev coj ua zoo tshaj plaws rau kev nyab xeeb thiab kev siv tau, kev xaiv cov txheej txheem kev lees paub thiab cov cuab yeej yuav tsum raug kho raws li daim ntawv thov cov cai tshwj xeeb thiab kev cia siab rau cov neeg siv kev sib cuam tshuam.
18. CORS yog dab tsi thiab koj ua li cas hauv Express.js?
Cross-Origin Resource Sharing, los yog CORS, yog ib qho kev ruaj ntseg ntxiv rau cov web browsers los tswj cov kev thov xa los ntawm ib lub npe mus rau lwm qhov. Nws ua kom a daim ntawv thov web uas ua haujlwm ntawm ib lub hauv paus chiv keeb tau tso cai nkag mus rau qee cov peev txheej los ntawm lwm lub hauv paus chiv keeb. Thaum tsim APIs rau cov neeg siv-sab web apps uas khiav ntawm ntau lub npe, hais txog CORS hauv Express.js tuaj yeem dhau los ua qhov tseem ceeb. Daim ntawv thov Express.js tuaj yeem yooj yim tswj CORS siv cov khoom nruab nrab zoo li pob cors. Cov neeg tsim tawm tuaj yeem tsim cov txheej txheem meej, xws li tso cai rau lub hauv paus tshwj xeeb lossis qhia meej tias HTTP txoj kev twg raug tso cai, los ntawm kev teeb tsa cov khoom nruab nrab no, muab kev tswj hwm zoo rau cov kev thov hla teb chaws. Kev tswj hwm CORS kom raug yog qhov tseem ceeb rau kev tso cai rau kev thov hla kev cai lij choj thiab khaws daim ntawv thov kev txwv kev nyab xeeb nyob rau hauv qhov chaw.
19. Piav txog React tivthaiv lub neej voj voog thiab cov txheej txheem cuam tshuam nrog cov txheej txheem kev ua neej sib txawv.
Lub React tivthaiv lifecycle qhia txog cov kauj ruam meej uas ib feem yuav tsum tau ua los ntawm lub sijhawm nws tau tsim kom txog thaum nws raug tshem tawm ntawm DOM, muab cov neeg tsim khoom hooks los ua cov cai ntawm qhov tseem ceeb junctures. Cov theem no thiab cov txheej txheem cuam tshuam muaj xws li:
Mounting: Cov khoom siv tau tsim thiab ntxiv rau DOM lub sijhawm no.
- constructor(): attaches event handlers and initializes lub xeev.
- render(): cov khoom sawv cev ntawm JSX rov qab los.
- componentDidMount(): ib zaug cov khoom tau ntxiv rau DOM; nquag siv rau kev muab cov ntaub ntawv.
Hloov kho: Thaum lub xeev lossis cov khoom ntawm cov khoom hloov pauv, nws tau tshwm sim.
- shouldComponentUpdate(): txiav txim siab seb yuav tsum muaj qhov kev qhia tshiab.
- render(): coj tshiab JSX rov qab ib zaug ntxiv.
- componentDidUpdate(): Tom qab hloov tshiab ua tiav; DOM kev sib cuam tshuam ua tau.
Unmounting: Cov khoom raug tshem tawm los ntawm DOM nyob rau theem kawg no.
- componentWillUnmount(): timers, event listeners, and any leftover subscriptions are cleared up.
20. Koj ua li cas rau kev ua kom zoo ntawm daim ntawv thov React?
Ib qho kev paub zoo ntawm cov neeg siv khoom yog nyob ntawm React daim ntawv thov kev ua tau zoo, uas tuaj yeem ua tau ntau txoj hauv kev.
Lub app tuaj yeem muab faib ua cov khoom me me los ntawm kev siv thev naus laus zis xws li React Lazy thiab Suspense kom ua tiav cov lej sib cais, thauj khoom tsuas yog cov ntsiab lus xav tau rau qhov muab saib.
Los ntawm kev ua ib qho kev sib piv ntawm cov khoom siv thiab lub xeev, PureComponent lossis React.memo tuaj yeem txo qhov tsis xav tau rov ua dua.
React Profiler, uas pab txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm
Kev txhim kho kev ua tau zoo kuj tuaj yeem ua tiav los ntawm kev ua kom zoo dua cov duab, txwv kev siv cov tsev qiv ntawv thib peb, thiab siv server-side rendering (SSR).
Cov neeg tsim khoom tuaj yeem tsim tau daim ntawv thov React uas teb tau ntau dua thiab ua haujlwm tau zoo thaum tseem ua rau cov neeg siv kev zoo siab los ntawm kev saib xyuas cov xwm txheej no thiab ua tib zoo saib ntawm daim ntawv thov kev ntsuas kev ua tau zoo.
21. Piav qhia txog qhov sib txawv ntawm cov khoom tswj thiab tsis tswj xyuas hauv React.
Qhov zais cia kom tswj tau cov ntaub ntawv tawm tswv yim zoo hauv React yog kom nkag siab qhov sib txawv ntawm cov khoom tswj thiab tsis tswj xyuas.
Cov neeg tsim khoom tuaj yeem tswj hwm qhov muaj txiaj ntsig thiab kev lees paub ntawm daim ntawv los ntawm kev siv cov khoom tswj hwm, uas muaj lawv cov tswv yim tseem ceeb tswj hwm los ntawm React lub xeev thiab txhua qhov kev hloov pauv rau cov tswv yim tswj hwm los ntawm kev ua haujlwm hauv cov khoom siv.
Hauv qhov sib piv, cov khoom tsis muaj kev tswj hwm tswj hwm lawv tus kheej hauv lub xeev thiab tawm hauv DOM los tswj cov nqi nkag.
Txawm hais tias txoj kev no yuav siv sij hawm tsawg dua, nws ua rau koj tswj tsawg dua li cas cov khoom coj. Cov khoom uas tsis muaj kev tswj xyuas tuaj yeem muab cov kev daws teeb meem ncaj qha rau cov kev siv yooj yim, thaum cov khoom siv tswj tau zoo dua rau cov ntaub ntawv nyuaj uas xav tau kev siv lub sijhawm tiag tiag thiab tus cwj pwm zoo.
Cov kev cai tshwj xeeb thiab qib ntawm qhov nyuaj ntawm daim ntawv hauv qhov teeb meem, nrog rau cov yam xws li qhov tsim nyog rau kev siv tau thiab kev tswj xyuas dav dav, yuav tsum ua raws li cov lus qhia rau kev txiav txim siab ntawm ob.
22. Koj siv React Hooks li cas, thiab qee qhov kev siv feem ntau yog dab tsi?
Lub peev xwm los txhawb lub xeev thiab lwm lub peev xwm React yam tsis tau tsim cov chav kawm ua tsaug rau React Hooks tau hloov pauv tag nrho li cas cov neeg tsim khoom tsim cov khoom.
Ib daim ntawv thov nquag yog useState nuv, uas ua rau cov programmers tswj hwm lub xeev hauv cov khoom siv ua haujlwm thiab muaj ntau txoj hauv kev los taug qab cov kev hloov pauv.
Raws li lwm txoj hauv kev ua neej nyob xws li componentDidMount, componentDidUpdate, thiab componentWillUnmount, useEffect nuv enables kev phiv xws li kev nqa cov ntaub ntawv thiab subscriptions.
Lwm cov hooks, xws li useContext, muab txoj hauv kev yooj yim dua ntawm kev nkag mus rau cov ntsiab lus tsis muaj cov khoom sib txuas, uas txhim kho cov lej nyeem.
Txawm tias muaj kev ywj pheej ntau dua los ntawm kev cai hooks, uas ua rau cov neeg tsim khoom tsim cov logic rov siv tau rau ntau yam. Kev siv cov hooks no ua rau muaj kev loj hlob sai, txhim kho cov cai tswj kev ruaj ntseg, thiab pab tsim kom muaj ntau dua thiab muaj txiaj ntsig React apps.
23. Koj puas tuaj yeem sau ib qho yooj yim React tivthaiv uas nqa cov ntaub ntawv los ntawm API thiab qhia nws?
Peb tuaj yeem tswj cov txheej txheem nqa tau yooj yim los ntawm kev siv cov useEffect thiab useState hooks. Nov yog ib qho piv txwv:
Thaum cov khoom txuas ntxiv, cov khoom siv ua haujlwm no tsim lub xeev rau cov ntaub ntawv, khaws nws los ntawm API teev, thiab qhia cov ntaub ntawv (lossis daim ntawv ceeb toom yog tias cov ntaub ntawv tseem tsis tau nkag mus tau). Nws yog tus qauv uas tuaj yeem hloov kho rau cov xwm txheej sib txawv thiab muaj txoj hauv kev zoo thiab muaj txiaj ntsig los tswj API cov ntaub ntawv hauv daim ntawv thov React.
24. Piav lub virtual DOM hauv React thiab nws ua haujlwm li cas.
React's virtual DOM (VDOM) yog lub tswv yim tseem ceeb uas txhim kho qhov browser rendering kom muaj txiaj ntsig thiab ua haujlwm ntawm cov apps. Nws ua haujlwm raws li qhov yooj yim hauv-nco rendition ntawm cov khoom tiag DOM.
React muab DOM virtual los cuam tshuam txog kev hloov pauv rau ib feem ntawm lub xeev lossis cov khoom siv es tsis ua cov kev hloov pauv rau DOM tiag tiag.
Cov kev hloov pauv tiag tiag raug txheeb xyuas los ntawm "kev sib haum xeeb," uas piv qhov kev sawv cev virtual no rau qhov kev rov ua ntej.
Hloov chaw rov ua dua tag nrho nplooj ntawv, React tom qab hloov kho tsuas yog cov hloov pauv hauv DOM tiag. Qhov kev xaiv hloov tshiab no txo qis kev tswj hwm DOM ncaj qha mus rau qhov tsawg kawg nkaus, txhim kho kev ua tau zoo thiab txhim kho cov neeg siv kev paub.
25. Koj tswj hwm kev vam meej hauv qhov project Node.js li cas?
Txhawm rau kom paub tseeb tias koj qhov haujlwm Node.js ua haujlwm tau zoo, kev tswj hwm kev vam meej yog qhov tseem ceeb. Node Package Manager (npm) yog lub cuab yeej tseem ceeb rau cov txheej txheem no vim nws ua rau nws yooj yim rau nruab, hloov kho, thiab tswj cov pob khoom los ntawm npm npe uas nws kim heev.
Koj tuaj yeem ntxiv ib pob tshiab rau koj qhov project siv npm install command, thiab nws yuav tshwm sim hauv koj cov ntaub ntawv package.json. Cov ntaub ntawv no ua haujlwm raws li qhov tshwm sim, sau tag nrho cov kev cia siab thiab koj qhov project tshwj xeeb versions rau txhua tus.
Cov ntaub ntawv pob-lock.json kuj ua kom paub tseeb tias qhov kev vam meej raug ntsia rau hauv txhua qhov chaw tsim nyog.
Cov neeg tsim khoom tuaj yeem tswj hwm qhov kev vam khom nyob hauv qhov project Node.js los ntawm kev siv cov cuab yeej thiab cov ntaub ntawv no, ua kom ntseeg tau tias muaj kev sib luag thiab muaj kev vam meej hauv kev txhim kho thiab xa tawm cov txheej txheem.
26. Piav qhov Event Loop hauv Node.js. Nws ua haujlwm li cas asynchronous?
Lub Event Loop, uas ua rau Node.js 'tsis-thaiv, asynchronous xwm, yog qhov tseem ceeb ntawm kev tsim. Nws yog ib lub voj uas tsis muaj qhov xaus uas scans qhov xwm txheej kab rau kev ua haujlwm, khaws lawv, thiab xa lawv mus rau qhov system hauv paus xov rau kev ua tiav.
Lub Event Loop hauv Node.js tso cai rau nws ua ntau yam kev ua ub no yam tsis tau tos rau ib txoj haujlwm kom tiav ua ntej mus rau tom ntej txij li nws siv ib txoj xov ntawm kev ua haujlwm.
Lub Event Loop tuaj yeem txuas ntxiv ua lwm yam dej num thaum muaj kev ua haujlwm asynchronous vim nws tau ntxiv rau hauv kab.
Ib qho kev hu rov qab tau ntxiv rau hauv kab tom qab qhov kev txiav txim asynchronous tiav thiab npaj txhij rau Event Loop los daws. Cov ntawv thov 'ceev thiab scalability tau txhim kho ua tsaug rau Node.js lub peev xwm los tswj ntau cov txheej txheem zoo.
27. Cov kwj hauv Node.js yog dab tsi, thiab koj yuav siv lawv li cas?
Node.js kwj yog cov cuab yeej siv tau zoo rau kev tswj cov ntaub ntawv, tshwj xeeb tshaj yog thaum ua haujlwm nrog cov khoom loj. Lawv nce kev ua tau zoo los ntawm kev tso cai rau cov ntaub ntawv los ntawm kev nce ntxiv es tsis yog tos kom tag nrho cov nyiaj them poob haujlwm.
Xav txog cov kwj deg zoo li cov kav dej uas nqa cov ntaub ntawv los ntawm ib qho chaw mus rau lwm qhov. Peb tuaj yeem nyeem los ntawm ib lub hauv paus thiab sau mus rau qhov chaw ua ntu zus los ntawm kev siv lawv.
Kev nyeem cov ntaub ntawv los ntawm cov ntaub ntawv, ua tiav tam sim ntawd, thiab faib rau cov neeg siv khoom yog cov piv txwv ntawm kev siv ntau zaus.
Node.js siv cov kwj tso cai rau kev nco-npaum cov ntaub ntawv ua haujlwm hauv cov ntawv thov thaum tib lub sijhawm optimizing ceev.
28. Koj ua li cas rau pawg hauv Node.js siv tag nrho CPU cores?
Node.js kev tuav ntawm pawg yog ib txoj hauv kev ntse kom ua tau zoo tshaj plaws ntawm tag nrho cov CPU cores, txhim kho daim ntawv thov kev ua tau zoo thiab kev ua tau zoo.
Vim yog ib qho xov xwm ntawm Node.js, kev sib koom ua ke ua rau muaj ntau yam txheej txheem me nyuam, uas tsom rau cov txheej txheem tseem ceeb ntawm ntau lub cores.
Cov haiv neeg "cluster" module tso cai rau cov neeg ua haujlwm tsim cov txheej txheem ua haujlwm uas sib koom cov chaw nres nkoj server nrog cov txheej txheem tseem ceeb. Los ntawm kev faib cov lus thov tuaj thoob plaws ntau tus neeg ua haujlwm, qhov no tau lees tias cov haujlwm ua haujlwm sib luag.
Hauv cov xwm txheej tsim khoom, kev siv cov kev sib koom ua ke feem ntau pom tias yog ib kauj ruam tsim nyog rau scalability thiab txhim kho kev siv peev txheej.
Cov neeg tsim khoom tuaj yeem siv nws los lav tias lawv daim ntawv thov Node.js tau npaj txhij los siv cov txheej txheem ntau yam, ua rau muaj kev ua tau zoo dua thiab kev vam khom.
29. Koj puas tuaj yeem sau cov haujlwm uas nyeem cov ntaub ntawv hauv Node.js siv ob qho kev hu rov qab thiab cov lus cog tseg?
Lub fs module, uas los preloaded nrog Node.js, muaj zog los cuam tshuam nrog callbacks thiab cog lus. Ua ib qho piv txwv, xav txog cov hauv qab no
Ob txoj hauv kev yuav nyeem "file.txt" cov ntsiab lus thiab luam tawm mus rau lub davhlau ya nyob twg. Lub tswv yim cog lus muaj ntau txoj hauv kev los txiav txim siab thiab tswj hwm asynchronous logic hauv kev sib piv rau txoj hauv kev hu rov qab, uas siv txoj hauv kev zoo los tswj cov haujlwm asynchronous hauv Node.js.
30. Sau ib txoj haujlwm los txuas rau MongoDB thiab khaws tag nrho cov ntaub ntawv los ntawm ib qho kev sau tshwj xeeb.
Kev txhim kho lub vev xaib nquag txuas nrog MongoDB thiab tau txais tag nrho cov ntaub ntawv los ntawm qee qhov sau. Nov yog txoj hauv kev yooj yim uas ua qhov no siv cov neeg tsav tsheb MongoDB:
Koj yuav tsum nkag mus rau qhov txuas url, lub npe database (dbName), thiab sau npe (collectionName) rau hauv txoj kev no. Cov haujlwm yuav xa rov qab txhua cov ntaub ntawv los ntawm cov khoom sau. Daim ntawv thov kev tswj xyuas tau zoo dua los ntawm kev siv async / tos, uas khaws cov cai tswj hwm thiab yooj yim nyeem.
31. Ua kom yooj yim CRUD API siv Express.js.
Express.js's CRUD API yog cov cuab yeej siv rau kev tsim, nyeem ntawv, hloov kho, thiab tshem tawm cov peev txheej hauv kev txhim kho online niaj hnub. Nov yog ib qho piv txwv ntawm CRUD API:
32. Tsim ib qho React tivthaiv uas siv lub xeev thiab cov khoom siv los ua cov ntaub ntawv.
Txhawm rau ua kom muaj kev cuam tshuam hauv React dynamic thiab hloov tau, nws yog ib txwm xyaum siv ob lub xeev thiab cov khoom siv thaum tsim cov khoom. Ntawm no yog ib qho piv txwv ntawm ib feem tseem ceeb:
Thaum UserProfile tivthaiv siv lwm qhov hauv daim ntawv thov, tus username prop yuav tsum tau muab. Hnub nyoog, ntawm qhov tod tes, yog lub xeev hloov pauv uas cov khoom tswj hwm.
Koj tuaj yeem nce lub hnub nyoog los ntawm kev nyem lub pob khawm, qhia txog daim ntawv thov tseem ceeb ntawm lub xeev los tswj cov ntaub ntawv dynamic. Cov duab no qhia txog yuav ua li cas los tsim cov khoom teb thiab rov siv tau los ntawm kev siv lub xeev thiab cov khoom siv.
33. Koj yuav ua li cas thiaj li daws tau cov ntaub ntawv uploads hauv Express.js?
Txhawm rau kom ua tiav cov txheej txheem seamless thaum tuav cov ntaub ntawv uploads hauv daim ntawv thov Express.js, qee qhov kev ntsuas tseem ceeb yuav tsum tau ua.
Ua ntej, koj feem ntau yuav siv ib pob zoo li multer, uas yog tshwj xeeb tshaj yog tsim los tswj cov ntaub ntawv multipart/form-cov ntaub ntawv, cov txheej txheem ib txwm upload cov ntaub ntawv los ntawm HTTP.
Ntawm no yog ib qho piv txwv ncaj qha ntawm tus txheej txheem:
Multiper tau teeb tsa hauv qhov qauv no los khaws cov ntaub ntawv upload hauv cov npe hu ua "uploads/." Los ntawm kev siv upload.single('file'), nws qhia Express kom txais tsuas yog ib cov ntaub ntawv nrog lub npe 'cov ntaub ntawv' los ntawm kev thov tuaj. Req.file yuav suav nrog cov ntaub ntawv hais txog cov ntaub ntawv uploaded.
34. Sau ib qho kev ua haujlwm nruab nrab hauv Express uas teev cov txheej txheem thov, URL, thiab teev sijhawm.
Kev debugging thiab tswj cov ntawv thov tuaj yeem pab tau zoo los ntawm kev tsim cov khoom nruab nrab hauv Express.js uas sau cov txheej txheem thov, URL, thiab sijhawm teev. Ntawm no yog ib qho piv txwv ntawm yuav ua li cas koj yuav ua tau xws li Middleware:
RequestLogger muaj nuj nqi nyob rau hauv no snippet ntawm code sau lub sij hawm ntawm lub sij hawm tam sim no, HTTP txoj kev (xws li GET, POST, thiab lwm yam), thiab qhov URL ntawm cov lus thov tuaj.
Nws ua kom paub tseeb tias qhov kev thov ua tiav mus rau cov khoom nruab nrab hauv qab no lossis tus neeg tuav txoj hauv kev hauv cov saw los ntawm kev ua tiav tom ntej ().
Qhov kev pom zoo ib yam ntawm daim ntawv thov kev sib cuam tshuam yog muab los ntawm kev ntxiv qhov kev cai nruab nrab no rau hauv daim ntawv thov thiab tom qab ntawd siv app.use() los siv rau txhua qhov kev thov tuaj.
35. Ua raws li cov neeg siv kev lees paub siv JWT hauv daim ntawv thov MERN.
Txhawm rau kom muaj kev ruaj ntseg tseem ceeb thiab siv tau cov ntaub ntawv pov thawj ntawm cov neeg siv, kev lees paub tus neeg siv khoom siv JWT (JSON Web Tokens) yuav tsum tau siv hauv MERN (MongoDB, Express.js, React, Node.js). Daim ntawv thov yuav tsim ib JWT ntawm lub backend thaum lub sij hawm nkag mus, uas siv tus yuam sij zais cia rau encrypt cov neeg siv cov ntaub ntawv. Ntawm no yog ib daim duab succinct:
Tom qab ntawd lub token tau txais kev cawmdim ntawm tus neeg siv khoom sab (React) thiab ntxiv rau cov npe ntawm cov lus thov tom ntej. Express.js tuaj yeem siv los tsim cov khoom nruab nrab ntawm sab server kom siv tau lub token:
36. Koj yuav ua li cas thiaj kuaj tau cov khoom tiv thaiv React? Sau cov ntaub ntawv sim yooj yim.
Cov tshuaj tiv thaiv React uas tau raug sim yuav ua haujlwm raws li qhov xav tau, uas ua rau muaj kev ruaj khov thiab muaj kev vam meej.
Feem ntau, cov ntaub ntawv xeem raug tsim thiab khiav siv cov tsev qiv ntawv zoo li Jest thiab React Testing Library.
Piv txwv li, koj tuaj yeem tsim cov ntaub ntawv ntsuas hauv qab no txhawm rau sim cov khoom ncaj nraim uas nthuav tawm lub pob nrog cov ntawv nyeem:
37. Tsim React nuv los tswj daim ntawv nkag.
Los ntawm kev cais cov logic rau kev hloov pauv cov tswv yim hauv kev cai React nuv, koj tuaj yeem txhim kho lub xeev kev tswj hwm hauv koj daim ntawv thov.
Qhov kev sib txuas no txhawb nqa txoj cai rov siv dua vim tias nws tuaj yeem siv rau ntau hom thiab cov khoom sib txawv. Ntawm no yog ib qho piv txwv ntawm yuav ua li cas sau ib tug nuv:
Tom qab ntawd, koj tuaj yeem siv tus nuv no hauv cov khoom siv ua haujlwm, piv txwv li, los ntawm kev hais lub npe const = useFormInput(”). Koj tuaj yeem txuas tus nqi thiab hloov tus neeg tuav ntaub ntawv mus rau lub ntsiab lus nkag los ntawm kev muab lub npe.value thiab name.onChange tsis.
Koj cov khoom tuaj yeem ua kom huv dua thiab yooj yim dua los tswj nrog qhov kev sib txuas ntawm daim ntawv tuav cov logic, tso koj lub sijhawm ua haujlwm rau lwm qhov chaw ntawm koj qhov kev pab cuam.
38. Ua yuam kev tuav rau ib txoj hauv kev hauv Express.js.
Express.js qhov kev ua yuam kev rau ib txoj hauv kev yuav tsum tau ua yog tias koj xav muab cov lus pom zoo rau cov neeg siv khoom thiab xyuas kom koj daim ntawv thov ua haujlwm tas li. Nov yog ib qho piv txwv ncaj qha los qhia koj tias koj tuaj yeem ua tiav qhov no:
Txoj kev tshwj xeeb /user/:id hauv cov qauv qauv no pom tus neeg siv los ntawm lawv tus ID. Ib qho kev ua yuam kev yog sib txuas lus mus rau cov khoom nruab nrab hauv qab no siv cov txheej txheem tom ntej yog tias nws tshwm sim, piv txwv li yog tias tus neeg siv tsis tuaj yeem nyob.
Cov khoom nruab nrab kawg hauv cov saw hlau sau cov teeb meem, xa tus neeg siv 500 tus lej raws li txoj cai, thiab sau qhov yuam kev.
Los ntawm kev siv tus qauv no, koj tuaj yeem muab kev txhim kho kev ua yuam kev thiab lav tias cov teeb meem uas tsis tau xav txog yog maj mam daws hauv koj daim ntawv thov.
39. Koj yuav ua li cas thiaj lis cov ntaub ntawv hauv lub sijhawm tiag tiag hauv daim ntawv thov MERN? Piav thiab sau tus lej snippet siv Socket.IO lossis cov thev naus laus zis zoo sib xws.
Siv cov kev daws teeb meem zoo li Socket.IO, kev tuav cov ntaub ntawv hauv lub sijhawm hauv MERN (MongoDB, Express.js, React, Node.js) daim ntawv thov tuaj yeem tswj tau zoo.
Yog li ntawd, cov neeg siv khoom thiab cov neeg rau zaub mov tuaj yeem sib txuas lus hauv ob qho lus qhia thiab tau txais kev hloov kho tam sim ntawd raws li cov ntaub ntawv hloov pauv. Koj tuaj yeem teeb tsa lub qhov (socket) hauv server (Express.js) raws li hauv qab no:
40. Piav qhia thiab siv caching hauv MERN daim ntawv thov kom ua tau zoo.
Los ntawm kev txuag cov ntaub ntawv yav dhau los-nrhiav thiab ua rau nws muaj rau kev thov yav tom ntej, caching yog ib qho tseem ceeb optimization mus kom ze hauv MERN daim ntawv thov uas tuaj yeem txhim kho kev nrawm. Qhov no txo cov sij hawm thauj khoom thiab txo cov neeg rau zaub mov ntawm qhov tsis xav tau kev ntxhov siab. Siv lub tsev qiv ntawv caching zoo li Redis hauv Express.js backend yog ib qho txheej txheem caching.
Koj yuav tsum xub configure Redis li koj lub khw cache:
Koj yuav txiav txim siab seb cov ntaub ntawv twb tau cached thaum tuav qhov kev thov:
xaus
Hauv kev xaus, kev nkag siab txog cov lus nug ntawm kev xam phaj hauv qhov tob tuaj yeem ua rau koj qhov kev txawj ntse MERN Stack.
Kev xyaum tsis tsuas yog ua kom zoo tag nrho; nws kuj tsim kev paub tob uas yuav paub qhov txawv koj hauv kev lag luam IT. Nco ntsoov tias kev ua tau zoo thiab kev kawm tsis tu ncua yog koj cov phooj ywg loj tshaj plaws thaum koj tshawb txog cov tswv yim no.
Nyob rau hauv ib qho kev sib tham MERN Stack lossis kev xam phaj, koj yuav tsis ntseeg siab yog tias koj paub zoo thiab paub txog tus kheej.
Rau kev pab nrog kev npaj xam phaj, saib Hashdork's Interview Series.
Sau ntawv cia Ncua